Electrical connector using plastic clamp

ABSTRACT

A non-corrosive connector includes a lead antimony alloy connector member having a compressible sleeve fitting a terminal post of a storage battery and a wire receiving portion which can be crimped about such wire. The connector also includes a clamp member of molded plastic material having a split ring portion extending around the split sleeve and provided with adjacent end elements having aligned holes through which a clamping screw also made of molded plastic material extends. One of the end elements has internal threads molded during the molding of the clamp member including separate sets of half threads molded on axially contiguous wall portions of the hole in such element. The sets of half threads are displaced from each other axially of such hole and are on opposite sides of such hole. An opening in the side of the hole opposite each set of half threads enables mold members having complementary threads to be employed to mold the threads.

United States Patent [1 1 Kelly [451 Sept. 4, 1973 ELECTRICAL CONNECTORUSING PLASTIC CLAMP {75] lnventor: Jerome Kelly, Portland, Oreg.

[73] Assignee: North American Manufacturing,

Inc., Portland, Oreg.

22 Filedz Sept. 30, 1971 [21] Appl. No.2 185,265

[52] US. Cl. 339/230, 24/125 R, 24/135 R [51] Int. Cl. H01r 11/26, F16g11/06 [58] Field ofSearch.....339/224-240,116,114,199;

[56] References Cited UNITED STATES PATENTS 3,356,988 12/1957 Gall339/227 X 3,397,382 8/1968 Shannon 339/230 R 3,636,504 1 1972Applegate... 339/228 2,806,724 9/1957 Anspach 287/118 2,077,821 4/1937Baird et al. 339/228 1,870,112 8/1932 Hand et al. 24/135 R FOREIGNPATENTS OR APPLICATIONS 212,398 12/1960 Germany 339/230 R PrimaryExaminer-Marvin A. Champion Assistant ExaminerWilliam F. Pate, llIAttorney-Stephen W. Blore, James Campbell, Jr. et a1.

['57 ABSTRACT A non-corrosive connector includes a lead antimony alloyconnector member having a compressible sleeve fitting a terminal post ofa storage battery and a wire receiving. portion which can be crimpedabout such wire. The connector also includes a clamp member of moldedplastic material having a split ring portion extending around the splitsleeve and provided with adjacent end elements having aligned holesthrough which a clamping screw also made of molded plastic materialextends. One of the end elements has internal threads molded during themolding of the clamp member ineluding separate sets of half threadsmolded on axially contiguous wall portions of the hole in such element.The sets of half threads are displaced from each other axially of suchhole and are on opposite sides of such hole. An opening in the side ofthe hole opposite each set of half threads enables mold members havingcomplementary threads to be employed to mold the threads.

7 Claims, 12 Drawing Figures PATENTEUSEP 4W 3.757.283

JEROME KELLY IN VEN TOR BUCKHORN, BLORE, KLARQUIST & SPARKMAN ATTORNEYSELECTRICAL CONNECTOR USING PLASTIC CLAMP BACKGROUND OF THE INVENTION Thecorrosion of parts of connectors employed to make electrical connectionsto the lead terminal posts of automotive storage batteries has been along standing problem. The type of connector which has been employed fora number of years on most cars and trucks has been a split clampingmember made of a lead-antimony alloy which extends around and fits abattery terminal post. A bolt extends through the ends of such memberand has a nut upon its threaded end. The bolt and not has been made offerrous metal because of strength requirements and even though the boltand nut may be provided with a protective coating, such coating doesnot, in general, remain effective. Corrosion of the bolt or nut bybattery acid usually occurs.

A number of connectors, which have internally threaded caps of plasticmaterial for clamping a split sleeve of a connector member on a batterypost by screwing the cap onto such split sleeve or which have a morecomplicated arrangement including an externally threaded plasticclamping plug screwed into an internally threaded bore in a plastichousing surrounding a split sleeve or equivalent connector member, havebeen proposed. These connectors have either not been capable ofmaintaining an effective electrical connection over long periods of timeor have been of complicated and expensive construction.

SUMMARY OF THE INVENTION The connector disclosed in the presentapplication provides a simple and inexpensive connector. It includesthree members only, all of which can be produced by injection casting orinjection molding operations. The cast or molded members require nomachining operations, even though one of the elements has internalthreads for screw threaded engagement with the threads of a clampingscrew.

The three members of the connector include a connector member made of anon-corrosive metal alloy which can be cast in its final form by aninjection casting operation using permanent molds. This connector memberhas a compressible sleeve fitting a terminal post of a storage batteryand a wire receiving portion which can be crimped about the conductorwire and insulation of a battery cable.

The three members also include a split or bifurcated clamp ring made ofplastic material which can be injection molded in final form includinginternal threads for receiving the threaded portion of a clamping screwextending through aligned holes in spaced but adjacent end elements ofsuch ring. By providing two sets of partial threads on opposite sides ofthe wall of a hole extending through one of the end elements of suchring with the sets of partial threads disposed axially of the holerelative to each other, two mold members each having partial threadscomplementary to one set of such partial threads can be employed to moldthe two sets of partial threads.

The clamping screw including its external threads can also be injectionmolded in its final form so that the three members of the connector canbe assembled by the user after the connector member has been crimped ona wire by employing a known type of hand actuated crimping tool of thecorrect size. The resulting assembly is sufficiently rugged to withstandcontinued use in cluding repeated installation on and removal from theterminal post of a storage battery.

An aligned hole in the other end element of the clamp ring is employedto keep the clamping screw in correct engagement with the partialthreads in the molded clamp ring. Such hole through the other endelement of the clamp ring can be molded by employing two mold members inthe same manner as the two mold members are employed to mold the partialthreads, except that the complementary threads can be omitted from themold members.

For other applications of such molded internal threads, where analigning hole in a separate portion of an article is not present, threeor more sets of partial threads can be em-ployed on angularly relatedside portions of the hole for the bolt or screw. It is also possible toomit one or more of the sets of partial threads to leave smooth sides ofthe hole while retaining the aligning function as long as at least oneset of partial threads is retained.

It is therefor an object of the invention to provide a simple andinexpensive non-corrosive electrical connector for the terminal post ofa storage battery.

Another object is to provide an internally threaded element forreceiving the threaded portion of a screw or the like, which internallythreaded element can be injection molded.

' BRIEF DESCRIPTION OF TI-IE DRAWINGS FIG. 1 is a plan view of aconnector in accordance with the present invention installed on theterminal post of a storage battery;

FIG. 2 is an end view of the connector of FIG. 1 with the terminal postof the battery omitted;

FIG. 3 is a plan view of the clamp member of FIGS. 1 and 2;

FIG. 4 is a sectional view taken on the line 44 of FIG. 3;

FIG. 5 is a side view of the clamping screw of FIGS. 1 and 2;

FIG. 6 is an end view of the clamping screw of FIG.

FIG. 7 is a side elevation partly in vertical section of the connectormember'of the connector of FIGS. 1 and FIG. 8 is a bottom view of theconnector member of FIG. 8;

FIG. 9 is a vertical section through a modified connector member;

FIG. 10 is a vertical section through another modified connector member;

FIG. 11 is a plan view of a modified internally threaded element, alsoshowing fragments of mold members for such element; and

FIG. 12 is a view showing the threaded element of FIG. 11 in verticalsection and the mold members in side elevation.

DESCRIPTION OF THE PREFERRED EMBODIMENT The embodiment of the connectorshown in FIGS. 1 to 8, includes a molded plastic clamp member 12 in theform of a split or bifurcated ring fitting the exterior of acompressible sleeve 14 forming part of a connector member 15. Such splitring 12 being separate from and axially movable of the sleeve 14 toenable assembly and disassembly. The connector member is preferably madeof a known or suitable lead-antiminy alloy so as to be corrosionresistant to storage battery acid.

The connector also includes a molded plastic clamping screw 16 extendingthrough aligned holes in the adjacent end elements 18 and 20 of theclamp member 12. The end element 20 is provided with molded internalthreads 22 for threaded engagement by the clamping screw 16 to enabletightening of the clamp member 12 about the split sleeve 14 to compresssuch sleeve about a battery post 24 shown in FIG. 1. The clamp screw 16may have any suitable type of head 17 enabling turning of the screw byhand or with a wrench or other tool.

The threads 22 in the end element 20 of the clamp member are dividedinto two sets of partial threads which are formed in wall portions 26and 28 of a hole 30 extending through such end element 20. The wallportions 26 and 28 are on opposite sides of the hole 30 and disposedaxially of such hole with respect to each other. These wall portions andthe molded sets of threads thereon each extend substantially 180 aroundthe hole. An opening 32 opposite each wall portion 26 and 28 extends tothe exterior of the end element. These openings 32 are formed as theresult of employing mold members to mold the wall portions 26 and 28 ofthe hole 30 including the partial threads 22 on such portions asexplained in connection with FIGS. 11 and 12.

A separate internally threaded element 34 having three sets of moldedpartial threads 22 is shown in FIGS. 11 and 12 along withdiagrammatically illustrated mold members 36 and 38. The mold members 36and 38 are shown as projecting from opposite walls of the mold cavityand no attempt has been made to show the complete mold, since such moldmay otherwise be a conventional mold for injecting molding having anumber of mold cavities for simultaneously molding a plurality ofelements. When the mold is closed, the mold members 36 and 38 occupypositions which result in producing the openings 32 in the internallythreaded element during a molding operation. Since the ends of the moldelements are rounded and have partial threads thereon complementary tothe partial threads 22, the result is the molding of the partial threads22.

It is apparent from FIG. 12 that the rounded ends of the mold members 36and 38 overlap and are in contact with each other and that mold wallswill be in contact with the upper and lower surfaces of the moldedelement 34 so that a hole 30 is formed which extends entirely throughthe molded element. It is also apparent that the two sets of partialthreads 22 shown in the end element 20 of FIGS. 1 to 4 can be molded byemploying two mold members, such as the mold member 36 and one of themold membPrs 38 of FIGS. 11 and 12, and that the hole 42 in the endellem'ent 18 of FIGS. 1 to 4 can be molded by merely omitting thecomplementary partial threads 40 on similar mold members. Furthermore,the threaded element 34 of FIGS. 11 and 12 can have all but one of thesets of partial threads 22 omitted to leave unthreaded wall portions ofthe hole 30, particularly for light duty applications.

The clamp member 12 of FIGS. 1 to 41 as well as the threaded element ofFIGS. 11 and 12 or the screw 16 may be made of any suitable highstrength plastic material which can be molded and which need not be thesame for all of such elements. Particular suitable materials are glassfilled polyethylene or polypropylene thermoplastic materials or variouscopolymers of these materials including copolymers of either or both ofsuch materials with other polymerizable materials, and also includingvarious other suitable modifiers known to the art. The glass filling ismade up of short pieces of very fine glass fibers.

The'connector member 15 of FIGS. 1 to 3 is shown in more detail in FIGS.7 and 8. The compressible sleeve of this connector member has an openend 44 for receiving a battery post and has a plurality of slots 46circumferentially spaced in the sleeve and extending axially from theopen end of the sleeve. The other end of the sleeve is closed and has aportion 48 of the wire connecting element 15 extending axially from saidclosed end. A wire receiving portion 50 extends at right angles to theportion 48 and has an axial bore 52. The bore 52 has a diameter adjacentthe portion 48 of a suitable size for receiving a conductor wire of abattery cable and a larger diameter adjacent its open end to receive theinsulation surrounding such wire. It is apparent that the wireconnecting element may be crimped on the wire and on the insulation of abattery cable by a suitable crimping tool.

The modified connector member 15' of FIG. 9 is the same as that of FIGS.7 and 8 except that it is provided with two wire receiving elements 50for receiving two different cables, and is useful, for example, forconnecting storage batteries in parallel.

The modified connector member 15" of FIG. 10 has a compressible sleeve14 which is open at both ends and has a wire connecting element 50extending at right angles from one end of the compressible sleeve sothat the connector member 15" requires less vertical clearance above thetop of a storage battery than the connector members 15 and 15 of FIGS. 7and 9, respectively.

The clamp member 12 of FIGS. 1 to 3 can be employed with any of theconnector members 15, 15' or 15" and has an axially extending internalrib 54 which fits any of the slots 46 in the compressible sleeves ofsuch connector members to prevent rotation of the clamp member about theaxis of the sleeve while at the same time enabling the clamp member sooccupy several angular positions on the sleeve.

I claim: 1. An electrical connector, comprising: connector meansincluding a connector member of non-corrodable metal having acompressible sleeve means adapted to fit a terminal post and means forconnecting a wire to said connector member;

clamping means for clamping said sleeve means to said post, including asplit ring member of molded plastic material extending around saidsleeve means and having adjacent end elements spaced from each other,said split ring member being separate from and movable axially of saidsleeve means;

and a thread clamping screw of molded plastic material extending throughaligned holes in said end elements.

2. The electrical connector of claim 1 in which:

said compressible sleeve of said connector member has a plurality ofslots extending axially of said sleeve means and said ring member ofsaid clamping means has an internal rib engaging in a selected one ofsaid slots to prevent relative rotation between said sleeve and saidclamping means.

3. The electrical connector of claim 2 in which:

said connector member has a portion extending axially from one end ofsaid sleeve means and terminating in a wire connecting element extendingat right angles to said portion;

said wire connecting element having its axis spaced from said split ringmember, being hollow for receiving the end of an insulated wire andbeing crimpable about said wire.

4. The electrical connector of claim 1 in which:

one of said end elements is provided with internal screw threads moldedin said plastic material for threaded engagement by said clamping screw.

5. The electrical connector of claim 1 in which:

one of said end elements has openings extending from opposite sides ofsaid one element past each 7. The electrical connector of claim 5 inwhich another of said wall portions positioned on the opposite side ofsaid hole also has internal partial threads molded thereon for threadedengagement by said clamp screw.

1. An electrical connector, comprising: connector means including aconnector member of non-corrodable metal having a compressible sleevemeans adapted to fit a terminal post and means for connecting a wire tosaid connector member; clamping means for clamping said sleeve means tosaid post, including a split ring member of molded plastic materialextending around said sleeve means and having adjacent end elementsspaced from each other, said split ring member being separate from andmovable axially of said sleeve means; and a thread clamping screw ofmolded plastic material extending through aligned holes in said endelements.
 2. The electrical connector of claim 1 in which: saidcompressible sleeve of said connector member has a plurality of slotsextending axially of said sleeve means and said ring member of saidclamping means has an internal rib engaging in a selected one of saidslots to prevent relative rotation between said sleeve and said clampingmeans.
 3. The electrical connector of claim 2 in which: said connectormember has a portion extending axially from one end of said sleeve meansand terminating in a wire connecting element extending at right anglesto said portion; said wire connecting element having its axis spacedfrom said split ring member, being hollow for receiving the end of aninsulated wire and being crimpable about said wire.
 4. The electricalconnector of claim 1 in which: one of said end elements is provided withinternal screw threads molded in said plastic material for threadedengagement by said clamping screw.
 5. The electrical connector of claim1 in which: one of said end elements has openings extending fromopposite sides of said one element past each other and having contiguousportions with rounded ends which overlap to provide said hole in saidone element and also provide wall portions of said hole in said oneelement which are on opposite sides of said hole in said one element anddisposed axially of said hole in said one element with respect to eachother.
 6. The electrical connector of claim 5 in which at least one ofsaid wall portions has internal partial threads molded thereon forthreaded engagement by said clamp screw.
 7. The electrical connector ofclaim 5 in which another of said wall portions positioned on theopposite side of said hole also has internal partial threads moldedthereon for Threaded engagement by said clamp screw.